1. Field of the Invention
The present invention relates to blower housings for furnace blower assemblies, the blower housings including an outlet for the attachment of a flue pipe.
2. Description of the Related Art
Blower assemblies are used in modern furnaces to increase the fuel efficiency of the furnace burner by inducing a draft through the furnace to draw heated air and products of combustion through a heat exchanger within the furnace and exhaust same through an exhaust pipe. Typically, the blower assembly includes a blower housing mounted to the furnace, the blower housing defining an impeller cavity therein. The blower housing also includes a mounting surface for mounting a motor to the blower assembly. The motor includes an output shaft to which an impeller is affixed, the impeller disposed within the impeller cavity. In operation, the motor rotatably drives the impeller to draw heated air and exhaust gases from the furnace into the blower housing and to exhaust the heated air and exhaust gases through the outlet of the blower housing into a flue pipe to direct the gases away from the furnace.
Although the addition of a blower assembly has been shown to substantially increase the efficiency of modern furnaces, the blower assembly adds to the overall cost of the furnace and therefore it is desirable to manufacture the blower assembly as economically as possible.
Some known blower housings include four or more individual components which are made of stamped metal, cast metal, or plastic materials. Generally, the more components which are used to form the blower housing, the easier it is to manufacture each of the components, such as by using conventional metal stamping and drawing processes. However, blower housings which include a large number of components have the disadvantage of requiring an increased parts inventory, and also may be somewhat difficult and labor-intensive to assemble.
One known blower housing is formed of two components of stamped/drawn metal which are secured to one another by crimping the edge portions of the pieces to one another. Although this type of construction results in a blower housing which is easy to assemble, the shapes of the two blower housing components requires complicated drawing operations to form the components, making the components somewhat difficult to manufacture and leading to increased tooling costs.
Also, different furnace manufacturers typically have different design requirements for the blower housings, and furthermore, each furnace manufacturer may have different design requirements for different furnaces throughout its product line. For example, the degree of offset, or spacing, of the blower housing outlet from the surface at which the blower housing is mounted to the furnace may vary. Thus, a blower housing which is designed for a particular furnace might not meet the specifications of other furnaces. This requires a manufacturer of blower housings to produce different blower housings of varying specifications in order to suit the needs of each furnace manufacturer.
What is needed is a blower housing for furnace blower assemblies which is an improvement over the foregoing.